pgw: Introduce test TC_s2b_createSession_v4_no_apco

This test allows initial testing of a session creation through the S2b
interface (emulating an ePDG).

A follow-up test will be added to test the APCO IE (feature which
open5gs-smfd still doesn't support).

Change-Id: I38e469edf0e00feca5a648035b64645e2c905937
diff --git a/library/GTPv2_Templates.ttcn b/library/GTPv2_Templates.ttcn
index 431415a..c842230 100644
--- a/library/GTPv2_Templates.ttcn
+++ b/library/GTPv2_Templates.ttcn
@@ -407,6 +407,20 @@
 }
 
 /* 8.17 */
+type enumerated GTP2C_RAT_Type {
+	GTP2C_RAT_reserved		('00'O),
+	GTP2C_RAT_UTRAN 		('01'O),
+	GTP2C_RAT_GERAN			('02'O),
+	GTP2C_RAT_WLAN			('03'O),
+	GTP2C_RAT_GAN 			('04'O),
+	GTP2C_RAT_HSPA_EVOLUTION	('05'O),
+	GTP2C_RAT_EUTRAN		('06'O),
+	GTP2C_RAT_Virtual		('07'O),
+	GTP2C_RAT_EUTRAN_NB_IoT		('08'O),
+	GTP2C_RAT_LTE_M			('09'O),
+	GTP2C_RAT_NR			('0A'O)
+} with { variant "FIELDLENGTH(8)" encode "RAW" };
+
 template (value) RAT_Type ts_GTP2C_RatType(template (value) integer rat) := {
 	elementIdentifier := '52'O,
 	lengthIndicator := 0, /* overwritten */
@@ -1046,6 +1060,7 @@
 			   template (present) GTP2C_Cause cause := ?,
 			   template FullyQualifiedTEID_List fteids := *,
 			   template PDN_AddressAllocation addr := *,
+			   template APN_Restriction apn_restriction := *,
 			   template BearerContextGrouped_List bctxg := *) :=
 tr_PDU_GTP2C(d_teid, seq, {
 	createSessionResponse := {
@@ -1055,7 +1070,7 @@
 		heNBInformationReporting := *,
 		fullyQualifiedTEID := fteids,
 		pDN_AddressAllocation := addr,
-		aPN_Restriction := ?,
+		aPN_Restriction := apn_restriction,
 		ambr := *,
 		linkedEPS_Bearer_ID := *,
 		protocolConfigOptions := *,